1. Field of the Invention
The present invention relates to an image processing apparatus for processing image data in parallel with a plurality of image processing units, and combining and outputting the processing results, and to a control method thereof.
2. Description of the Related Art
With conventional image processing that involves reading, image processing and printing an original document, image data obtained by reading the original document is processed by a single image processing unit. Meanwhile, as an image processing apparatus for processing high resolution image data at high speed, it is proposed to divide the image data of an original document into a plurality of sections (region division), and process these divided pieces of image data in parallel with a plurality of image processing units (Japanese Patent Laid-Open No. 2006-171864).
The above conventional image processing units perform image processing that involves shifting image data in a main scanning direction and is dependent on positioning in the main scanning direction. Also, an apparatus that performs image processing in parallel using a plurality of image processing units will require an image combining unit for restoring the plurality of divided image data that have been processed to the original image. In this case, if a plurality of image processing units respectively perform image processing on image data that has been divided and transferred, correct position information corresponding to the original image before being divided will not be provided for the divided image data. A unit for shifting image data in the main scanning direction and a unit for performing image processing dependent on positioning in the main scanning direction are thus mounted in the image combining unit. A shift in the main scanning direction and image processing dependent on positioning in the main scanning direction need to be performed after combining the image data with this image combining unit and obtaining the correct position information of the original image.
However, with such an image processing apparatus, the unit for performing a shift in the main scanning direction and the unit for performing image processing dependant on positioning in the main scanning direction need to be mounted redundantly in both the image processing unit and the image combining unit. Thus, there is a problem in terms of the increased cost of the overall system.